Fiber optic infrastructure now being deployed by certain telecommunication companies can be operatively connected to customer premises. Such fiber optic infrastructure offers many advantages over traditional copper-wire cabling, including vastly increased bandwidth.
The well known plain old telephone system (POTS) operated, and still operates, with copper wiring. POTS is now being made compatible with fiber optic cabling.
However, a POTS telephone system in combination with fiber optic infrastructure involves certain optically-related and/or other functionality not previously utilized in the traditional all-copper systems. For example, an optical line terminal (OLT) is now typically located in a central office of the telecommunications company or at some other regional location (but typically not on customer premises).
The central office OLT can be communicatively coupled via fiber optic cable to an Optical Network Terminal (ONT) located at or near the customer premises. The ONT can be situated immediately outside of a customer premise (e.g., mounted on an outside wall several feet above ground). However, the ONT is, more and more, being placed inside the customer premises, where space is typically at a premium.
The ONT may be powered, for example, by a power supply such as that described in U.S. patent application Ser. No. 11/144,566, filed Jun. 3, 2005, which claims the benefit of U.S. Provisional Application Ser. No. 60/576,675, filed Jun. 3, 2004, and which is incorporated by reference herein in its entirety. Such a power supply can, in turn, be powered by typical electric utility company power which is subject to power failure for reasons including, without limitation, natural disasters and terrorist attacks.
During a utility company power failure, traditional POTS telephone service over copper wiring is ordinarily able to continue because of POTS battery back-up infrastructure which is in place at telecommunication company central offices. This battery backup system is designed to maintain POTS telephone service for an entire community. However, that otherwise-available emergency POTS telephone service shall not be available to a telephone customer using a Fiber-to-the-Premises (FTTP) system, if the ONT at the customer premise cannot communicate with the central office OLT via the fiber optic cable due to the ONT lacking power as a result of the power failure.
Consequently, battery backup has also been provided within the FTTP environment for the ONT and for customer telephone instruments connected to the ONT. But, if such a backup battery is used in a less than optimum manner, it can be quickly depleted. In such case, the customer shall have no back-up power with which to make telephone calls, including emergency telephone calls. Also, large back-up batteries consume more space than smaller back-up batteries, and with the ONT now often being located inside the premises, the issue of battery size becomes more important than when the ONT was located outside. Thus, there is a need for controlling battery back-up in an improved and efficient manner while using a smaller rather than a larger battery.